Short interfering RNAs (siRNAs) are used to induce gene silencing. They are a class of biological molecules that have the potential to be next generation therapeutics (Braasch et al, 2003). However, due to issues related to delivery, stability, and off-target effects, siRNAs still require some forms of chemical modification to make them appealing pharmaceutical candidates (Selvam et al, 2017; Lee et al, 2016).
Several chemical modifications have been explored to overcome many of the issues associated with structure (Corey et al, 2007; Kitamura et al, 2016). In addition, many different packaging systems have been utilized and studied to assist in localizing the siRNA to the correct tissue (Young et al, 2016). Despite advances, several issues still exist, notably off-target effects, i.e. tissue specific targeting. In order to reduce off-target effects and potentially activate an RNA at the desired target, methods that turn the siRNA on or off are desired.